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Biomedical subjects

G B Singh

Publications and source records attributed to G B Singh.

At least 19 recordsLinked to original sources
PubMed2007

Axillary hyperhidrosis: a 5-year review of treatment efficacy and recurrence rates using a new arthroscopic shaver technique.

BACKGROUND: Axillary hyperhidrosis is a chronic condition characterized by excess axillary perspiration. This results in considerable patient morbidity, with no consistently efficacious medical or surgical treatment method described in the literature. METHODS: All cases of axillary hyperhidrosis over a 5-year period were reviewed retrospectively. Data were gathered by a chart review and telephone interview. Inclusion criteria included primary hyperhidrosis, failed conservative therapy, no prior surgical therapy, surgical management using a new arthroscopic shaver technique (R.L.B.-S.), and 6 months of postoperative follow-up. The technique used was consistent between surgeons. Sweating severity was assessed using a subjective numerical rating scale ranging from 1 to 10. Patient demographics, symptom history, results, and complications were analyzed. RESULTS: Average follow-up for 50 patients meeting the inclusion criteria was 28 months. The subjective severity scale demonstrated severity of 9.8 of 10 preoperatively and 2.3 of 10 postoperatively. Three patients (6 percent) reported mild recurrence of symptoms (4.6 of 10), which was not severe enough to seek further treatment. The average follow-up of those patients was 18.5 months. An overall subjective satisfaction of 96 percent was found, with a treatment success rate of 94 percent. Complications were minimal and self-limiting. The average time away from employment was 3.9 days and the average surgical operating room time was 46 minutes. CONCLUSIONS: The authors' new arthroscopic shaver technique is efficacious, with no significant morbidity, a 96 percent satisfaction rate, a subjectively measured 75 percent reduction of sweat, and a recurrence rate of only 6 percent. For cases of primary hyperhidrosis affecting the axilla not amenable to conservative treatment, the authors recommend an arthroscopic shaver technique as the first-line treatment of choice.

Adolescent↗
PubMed1999

The prevalence of HIV in female sex workers in Manipur, India.

Data on STDs and sexual practices in commercial sex workers (CSWs) is in general limited in India. Manipur in north-east Indian has a high prevalence of HIV in injecting drug users but the rate in CSWs is not known. The site selected for the study was Moreh, on the Myanmar border of Manipur. One hundred blood samples were collected, 7 from migrants from Myanmar, the remainder from Manipuri women. The HIV seropositivity rate was 12% (95% CI = 5.6-18.4). The age of the women ranged from 15 to 42 (mean = 24.5 years, median 23.7 years). The proportion of HIV positives increased significantly with number of customers per day and number of years in the profession. The HIV prevalence among Injecting drug using CSWs was 9.4 times higher that among non-IDU CSWs. Vaginal discharge was strongly associated with HIV positivity. Effective intervention programmes among CSWs in Manipur to prevent further spread of HIV are strongly indicated by the results of this study.

Adolescent↗
PubMed1998

MARs mission update.

Genes are organized as chromatin domains and positioned in the nucleus through regions of nuclear matrix association, termed MARs. Although well-studied, the mechanisms regulating expression of the beta-globin locus remain an enigma. Here, we show that certain MAR sequences of the beta-globin locus are conserved and reiterated throughout the genome in association with other genes of the hematopoietic lineage. Further, the density of the MARs within the beta-globin locus and the sharing of these sequences by the various members of this gene cluster suggest that they may provide critical gene regulatory components.

Base Sequence↗
PubMed1998

A matrix associated region localizes the human SOCS-1 gene to chromosome 16p13.13.

The MarFinder algorithm was applied to a newly sequenced segment of 16p13.13 abutting the 3' end of the human PRM1-->PRM2-->TNP2 locus. A candidate region of matrix attached was identified. Subsequent biophysical analysis showed that this region was attached to the somatic nuclear matrix. Nucleotide sequence analysis also revealed the presence of a CpG island. Data base queries showed that this region contained the SOCS-1 gene. Thus, the SOCS-1 gene is bounded by a somatic MAR and is just 3' of the spermatid-expressed PRM1-->PRM2-->TNP2 domain at position 16p13.13.

Carrier Proteins↗
PubMed1997

Mathematical model to predict regions of chromatin attachment to the nuclear matrix.

The potentiation and subsequent initiation of transcription are complex biological phenomena. The region of attachment of the chromatin fiber to the nuclear matrix, known as the matrix attachment region or scaffold attachment region (MAR or SAR), are thought to be requisite for the transcriptional regulation of the eukaryotic genome. As expressed sequences should be contained in these regions, it becomes significant to answer the following question: can these regions be identified from the primary sequence data alone and subsequently used as markers for expressed sequences? This paper represents an effort toward achieving this goal and describes a mathematical model for the detection of MARs. The location of matrix associated regions has been linked to a variety of sequence patterns. Consequently, a list of these patterns is compiled and represented as a set of decision rules using an AND-OR formulation. The DNA sequence was then searched for the presence of these patterns and a statistical significance was associated with the frequency of occurrence of the various patterns. Subsequently, a mathematical potential value,MAR-Potential, was assigned to a sequence region as the inverse proportion to the probability that the observed pattern population occurred at random. Such a MAR detection process was applied to the analysis of a variety of known MAR containing sequences. Regions of matrix association predicted by the software essentially correspond to those determined experimentally. The human T-cell receptor and the DNA sequence from the Drosophila bithorax region were also analyzed. This demonstrates the usefulness of the approach described as a means to direct experimental resources.

Base Sequence↗
PubMed1997

Effects of Boswellia serrata gum resin in patients with ulcerative colitis.

Ulcerative colitis is a chronic inflammatory disease of the colon where leukotrienes are suggested to play an important role for keeping inflammation active. Boswellic acids, the biologically active ingredients of the gum resin of Boswellia serrata (Sallai guggal), have been shown to be specific, nonredox and noncompetitive inhibitors of 5-lipoxygenase, the key enzyme of leukotriene biosynthesis. In patients suffering from ulcerative colitis grade II and III the effect of Boswellia serrata gum resin preparation (350 mg thrice daily for 6 weeks) on stool properties, histolopathology and scan microscopy of rectal biopsies, blood parameters including Hb, serum iron, calcium, phosphorus, proteins, total leukocytes and eosinophils was studied. Patients receiving sulfasalazine (1 g thrice daily) served as controls. All parameters tested improved after treatment with Boswellia serrata gum resin, the results being similar compared to controls: 82% out of treated patients went into remission; in case of sulfasalazine remission rate was 75%.

Abdominal Pain↗
PubMed1996

Computer-assisted search for sites of nuclear matrix attachment.

This communication describes a useful approach for assessing the significance of the occurrence of multiple motifs within defined segments of the genome. Regions of potential biological importance are identified using various sequence motifs, and then the results are displayed as their cumulative statistically weighted distribution. We illustrate the utility of this strategy to the search for known nuclear matrix-associated regions by its application to the human beta-globin and other loci.

Algorithms↗
PubMed1995

CLONEPLACER: a software tool for simulating contig formation for ordered shotgun sequencing.

This communication describes a software tool that enables one to simulate large-scale regional mapping using an ordered shotgun sequencing approach. The analysis routines that are provided yield an estimate of the depth of coverage of the physical map, the largest contig formed, and the number of gaps remaining at any given juncture in the project. A detailed listing describing the span of each contig within the physical map is also presented. This provides an a priori means of estimating the resources that will be required to undertake any megabase mapping or sequencing project. CLONEPLACER provides the much needed guide to deriving the optimal strategy.

Chromosome Mapping↗
PubMed1995

DNAView: a quality assessment tool for the visualization of large sequenced regions.

This communication describes DNAView, a graphical tool for the visualization and printing of large nucleic acid sequences. DNAView uses color coding to compactly display genomic segments of up to 100 kb on a single printed page. The specific color schemes integrated into DNAView can highlight 'local aggregate' properties of large segments of DNA. We have also incorporated a confidence expression for the assigned sequence. This is represented by base color intensity that is proportional to the number of times that base was sequenced. Areas of interest, such as exons, introns, repetitive elements and splice sites, can be emphasized using overlays. The colored image can be saved in a standard TIFF image file format that may be imported and annotated by other application software.

Base Sequence↗
PubMed1995

Testicular toxicity of Di(2-ethylhexyl)phthalate in developing rats.

To understand the factors involved in the enhanced testicular toxicity of di(2-ethylhexyl)phthalate (DEHP) in developing animals, po doses of 50, 100, 250 or 500 mg DEHP/kg were administered to 25-d-old albino rats for 30 consecutive days. Activities of testicular and hepatic cytochrome P-450 enzymes were determined. A dose-dependent increase in the activities of lactate dehydrogenase and gamma-glutamyl transpeptidase and a decrease in sorbitol dehydrogenase was observed in the testes. The activity of beta-glucuronidase increased at dosages of 250 and 500 mg/kg, while acid phosphatase decreased. Testes had marked destructive changes in the advanced germ cell layers at dosages of 250 and 500 mg/kg, which supports biochemical studies indicating that DEHP interacts with the maturation process of the testes. The dose-dependent decrease in hepatic cytochrome P-450 levels and the activities of ethylmorphine N-demethylase and aniline hydroxylase suggest that impaired metabolism of DEHP could lead to higher amounts of the diester or its metabolites reaching the testes; this may result in enhanced vulnerability of the testes to DEHP in developing animals.

Aging↗
PubMed1995

2-(2,3-dimethylchromon-6-yl) propanoic acid (OVS-103): a potent anti-inflammatory agent.

The compound OVS-103 showed dose-dependent anti-inflammatory and anti-arthritic effects in different acute and chronic test models in rats and mice. It produced inhibition of the exudate volume and the migration of leucocytes in the carrageenan induced pleurisy test in rats. OVS-103 showed poor inhibitory effect on granuloma formation induced by cotton pellet and had no anti-pyretic and analgesic property. ALD50 in both rats and mice was more than 2000 mg/kg, p.o. and 1500 mg/kg, i.p.

Animals↗
PubMed1994

Attenuation of benzanthrone toxicity by ascorbic acid in guinea pigs.

Oral administration of benzanthrone (BA) (50 mg/kg body wt/day) to guinea pigs for 30 days resulted in depletion of ascorbic acid (ASA) in the liver, adrenals, and blood serum and in growth retardation (36%) and an increase (18%) in relative liver weight when compared to controls. BA treatment showed a tendency toward normocytic anemia with a decrease in hemoglobin content, reduction in RBC counts, and lowered packed cell volume. Guinea pigs treated with BA showed histopathological changes in liver including fibrosis, bile duct proliferation, and focus necrosis. Testes showed marked damage of seminiferous tubules with vacuolar degeneration and irregular and distorted interstitial spaces. BA showed evidence of patchy glomerular congestion, tubular lesions, and damaged epithelial cells in kidney, while urinary bladders had mild congestion in lamina propria and submucosa. Hepatic GOT, GPT, and LDH were found to be significantly decreased (17.5-33.5%), whereas activities of these enzymes showed a significant elevation in serum of BA-exposed guinea pigs. BA treatment also led to significant decrease of testicular hyaluronidase (29.8%) and LDH (19.8%) and significant depletion of lactic acid content (14.7%). Prior daily oral supplementation with ASA (50 mg/kg body wt) to BA-administered guinea pigs resulted in marked improvement of histopathological and biochemical changes observed in liver, testis, kidney, and urinary bladder of BA-exposed animals. These results suggest that extra supplementation of ASA could attenuate the toxic manifestations of BA.

Animals↗
PubMed1994

ISWAC: proposed system for the integrated assembly of chromosomes.

The generation of a physical map as an integral part of sequence project management is a problem that present computer systems do not address. Primarily, the analysis performed is based solely on the information available from a single knowledge level. Management systems that are currently available do not adequately model the multi-layer top down strategy that is most often utilized to manage large scale sequencing projects. Single layered approaches reflect an algorithmic inadequacy since interacting data sets are required to provide a good solution. The analysis tool that is currently under development termed ISWAC, the Integrated System for Wholistic Assembly of Chromosomes, overcomes these limitations by integrating information available from five layers of knowledge. These knowledge layers utilize information from the linkage map, physical map, restriction map, clone strategy map and the DNA sequence itself. The approach we are implementing, reviews current project status and continually refines the experimental strategy necessary to efficiently complete the sequencing task. To facilitate project completion the system is designed to interactively recommend strategies based on partial information. The utility of this tool is enhanced by implementing knowledge representation techniques that allow reasoning with approximate concepts characteristic of these data-sets. In addition, the raw physical data is maintained within an integrated map database to ease data verification. This paper presents the first discussion of the design specifications for a computer system to assimilate the various forms of data that are being generated as part of the human genome project. It was specifically written to stimulate discussion regarding data standardization, translation, analysis and most important, an understandable user-interphase for the molecular biologist. We would hope that interested readers would respond by assisting in the definition of a set of universal data standards and adopting them in their laboratories.

Algorithms↗
PubMed1994

Anti-inflammatory properties of 3-methylpyrazolin-5-(4 H)-one-4-[3'-methoxy-4' (2'',3'',4'',6''-tetra-O-acetyl-beta-D-glycopyranosyl]benzylidene (compound IIIA).

Oral treatment of compound IIIA exhibited dose related inhibitory action in acute tests of carrageenan, histamine and dextran-induced oedema in rats. Marked inhibitory action of the compound was found when it was administered intraperitoneally in animals. It displayed prominent anti-arthritic activity in chronic tests of adjuvant and formaldehyde-induced arthritis in rats. It prevented the arthritis associated rise in total leucocyte count and erythrocyte sedimentation rate. It also lowered the levels of exudate volume and migration of leucocytes in carrageenan induced pleurisy in rats. It did not exhibit any analgesic, antipyretic or ulcerogenic effect. No mortality was recorded up to 2 g/kg in mice on oral or intraperitoneal treatment over a period of 72 hr.

Animals↗
PubMed1993

Modulation by ascorbic acid of the cutaneous and hepatic biochemical effects induced by topically applied benzanthrone in mice.

Modulation of biochemical markers by ascorbic acid was investigated in mice to which benzanthrone (BA) was applied topically (150 nmol/mouse) twice a week for 34 wk. After BA exposure without ascorbic acid, in the skin there were significant decreases in the activities of aryl hydrocarbon hydroxylase (AHH; 38% decrease relative to controls) and ethoxyresorufin-O-deethylase (EROD; 39%), and enhancement of the activities of quinone reductase (41% increase), tyrosinase (82%) and histidine decarboxylase (HDC; 190%). BA exposure also caused significant inhibition of hepatic AHH, EROD and glutathione-S-transferase activities, with concomitant increases in the activities of histidase (52%) and HDC (58%). Ascorbic acid given orally (5 mg/mouse) or topically (1 mg/mouse) twice weekly for 34 wk to BA-treated mice resulted in substantial protection against the effects of BA on these enzyme markers in both the skin and the liver. These results suggest that ascorbic acid could be useful in preventing the biochemical and toxicological manifestations caused by BA in laboratory animals.

Administration, Topical↗
PubMed1992

Comparative study of the biodisposition of benzanthrone in different rodent species.

The bio-elimination and organ retention of [14C]benzanthrone, an anthraquinone dye intermediate, were determined in rats, mice and guinea pigs. Urinary excretion of benzanthrone during 96 hr was higher in guinea pigs (28%) compared with rats and mice (19%). However, faecal elimination during 96 hr was higher in rats (39%) and mice (42%) than in guinea pigs (25%). Urinary elimination of benzanthrone in rats and mice was highest between 12 and 24 hr, while guinea pigs showed a peak value between 24 and 48 hr. The maximum amount of radiolabelled benzanthrone was eliminated through faeces at 24-48 hr in all the three animal species. The retention of [14C]benzanthrone in the liver was comparable in rats (11.2%) and mice (11.9%), while in guinea pigs it was substantially higher (21.9%). The testes of rats and mice were devoid of radioactivity, whereas those of guinea pigs showed a marginal retention (1.25%) of 14C. The present study suggests that guinea pigs are more prone to benzanthrone toxicity than are rats and mice since the bio-elimination of this compound is slower and its organ retention is higher in this species.

Animals↗